The present invention relates to a personal air transport or "PAT" which is capable of taking off and landing vertically as well as hovering, if desired. The PAT can maneuver, forward and back as well as side to side, and is capable of traveling forward at a reasonable speed.
Small vertical take-off and landing (VTOL) aircraft have been constructed in various configurations. The most well known is the helicopter which operates with powered rotor blades arranged above the craft body that rotate about a substantially vertical axis, and a powered tail rotor that rotates about a substantially horizontal axis. The pitch of the tail rotor blades is controlled in the cockpit by two pedals--one for the right foot and one for the left--which permit the operator to rotate the craft about the vertical axis or to hold it in a fixed, stable orientation by pressing on the right or left pedal, as desired. The pitch of the upper rotor blades is controlled by two levers: an up-down lever which changes the pitch if all blades at once and a directional "joystick" that selectively changes the pitch of the blades as they rotate through a 360.degree. arc. The joystick is used to tilt the craft and thus impart lateral motion.
Another craft which is capable of VTOL utilizes shrouded rotor blades for extra lift. Instead of arranging the lifting blades in open air, as in the case of a helicopter, they are placed in a vertical "wind tunnel". As air is drawn in, it passes over a smooth upper rim of the tunnel, reducing the air pressure on this rim in accordance with Bernoulli's Principal. Such a shroud thus not only prevents the air from exiting outward, horizontally from the rotor blades, it also adds lift by this application of Bernoulli's Principal, thereby adding a multiple of about 1.5 to the static thrust as compared to an unshrouded set of rotor blades.
VTOL craft which utilize shrouded rotor blades are therefore considerably more efficient and require less energy to remain airborne. Aircraft of this type are known from the U.S. Pat. Nos. 3,614,030; DES 292,194; 5,213,284 and 5,881,970.
For one reason or another, none of these aircraft designs has risen to the level of commercial practicality.